A conventional magnetic recording head includes a transducer deposited on a back surface of a slider. The slider also includes an air-bearing surface (ABS) that faces the recording media. FIG. 1 depicts a portion of conventional perpendicular magnetic recording (PMR) transducer 10 as viewed looking towards the ABS (not shown). The conventional PMR transducer 10 includes a conventional pole 16 and a top shield 24 separated by a write gap 20. Note that the top shield 24 also acts as pole during writing using the conventional PMR transducer 10. The conventional pole 16 and the top shield 24 are surrounded by insulating layers 18 and 22. The conventional pole 16 resides on a seed layer 12 and has sidewalls 14 and 15.
In conventional applications, the height of the conventional pole 16 is typically less than approximately three-tenths micrometer. The conventional pole 16 also has acute angles between the seed layer 12 and the sidewalls 14, 15 of the pole, such that the top of the conventional pole 16 is wider than the bottom of the conventional pole 16. Stated differently, each angle θ of the sidewalls 14, 15 is less than 90 degrees in the conventional pole 16 of FIG. 1. A pole having this height and shape is desirable for use in PMR applications.
FIG. 2 depicts a conventional method 50 for forming the conventional PMR head 10. A seed layer 12 for the conventional pole 16 is deposited and the pattern for the conventional pole 16 formed, via steps 52 and 54, respectively. The material for the conventional pole 16 is plated, via step 56. The remaining seed layer around the conventional pole 16 is removed, via step 58. The conventional pole 16 is then trimmed, via step 60. Consequently, the width of the conventional pole 16 and the negative angle are set in step 60. The insulator 18 is deposited around the conventional pole 16, via step 62. The insulator is typically alumina. A chemical mechanical planarization (CMP) is performed to planarize the surface and expose the conventional pole 16, via step 64. The surface is planarized in order to allow subsequent processing to be performed as desired. The write gap 20 is provided, via step 66. The top shield 24 that also acts as the pole is deposited and patterned in step 68. Finally, the region around the top shield 24 is insulated, via step 70.
Although the conventional method 50 can be used to form a conventional PMR head 10, the variation in the CMP process used in exposing the conventional pole 16 in step 64 has a relatively large vertical variation. For example, the three-sigma variation in the CMP may be on the order of three-tenths micrometer. Thus the variation in the CMP process can be on the order of the height of the conventional pole 16. As a result, the height of the conventional pole 16 may be extremely difficult to control and fabrication of suitable conventional PMR heads 10 difficult to repeat. Manufacturing of conventional PMR heads 10 may, therefore, have a very low yield.
Accordingly, what is needed is an improved, repeatable method for fabricating a PMR head.